Physiological sensor placement and signal transmission device

ABSTRACT

A garment is used to facilitate the placement of biomedical sensors or other electrodes on the body. The garment is comfortable and allows freedom of movement much like typical clothing. Textile based electrical components are included in the garment which are capable of transmitting an electrical signal to and from various external electrodes placed on the body. A textile based EMI shield protects the signals from electromagnetic interference. The garment may take any form such as a vest, sports bra, long sleeve shirt, bonnet, or other form and may provide access to an electrode placement site without requiring removal of the garment.

BACKGROUND

1. Technical Field

The present disclosure relates to the monitoring and transmission ofelectrical signals for medical purposes. In particular the disclosurerelates to a garment capable of transmitting electrical signals such asbiopotential signals from ECG electrodes.

2. Background of Related Art

Electrocardiograph (ECG) monitors and recorders are widely used toobtain medical signals containing information indicative of theelectrical activity associated with the heart and pulmonary system. Toobtain these biopotential signals, electrodes are applied to the skin ofa patient or other subject in various locations and coupled to an ECGmonitor. The number of electrodes applied and placement locations of theelectrodes are dependant on the type of information sought by theclinician.

Conventional electrocardiography protocols have established severalstandard lead configurations for the placement of ECG electrodes on thesubject's skin. A standard 3-lead configuration, for example, requiresthe placement of three electrodes; one adjacent to each clavicle bone onthe upper chest and a third adjacent to the lower left abdomen. Astandard 12-lead configuration requires the placement of ten electrodes;six are placed at various locations on the patient's chest near theheart, and four are placed to represent each of the subject's limbs. Theright leg electrode is typically designated as the ground, and twelvemeasurements are then taken from the ten electrodes. These measurementsinclude six measurements from the six chest electrodes, threemeasurements of the difference in potential between two limbs, and threemeasurements of the difference between the potential at one limb and theaverage of the potentials at two other limbs. In addition to the 3-leadand 12-lead configurations, other standard configurations have beendeveloped. The most prevalent among these are the 5-lead and 7-leadconfigurations.

Once placed on the skin of the subject, electrodes are normallyconnected to a lead set which is then connected to an ECG monitor. TheECG monitor receives the biopotential signals from the body andprocesses the data such that the information can be interpreted by aclinician. The quality of information produced is dependant on severalfactors. Among these are the proper placement of the electrodes,consistent placement of the electrodes relative to one another andproper connection of the lead set to the proper electrodes.

A clinician may find it cumbersome to make the proper connections with alead set involving many wires which often tangle, and may find itdifficult to determine exactly which individual wire is to be connectedat which point. Also, a subject will often experience discomfort whileconnected to a traditional lead set. The subject's movement may belimited and the wires may cause some skin irritation.

SUMMARY

There is a need for an apparatus to alleviate some of the difficultiesinvolved with a traditional ECG lead set. Accordingly, the presentdisclosure is directed to an apparatus for facilitating the connectionof a biomedical electrode array to a monitoring, diagnostic, orstimulating device. The apparatus includes a garment member that may bepositioned on a body portion of a subject. At least one signaltransmission pathway is formed in the garment member and includes aconductive thread passed through the garment member to connect thesignal transmission pathway to the garment member. The signaltransmission pathway has a first end connectable to a biomedicalelectrode a second end connectable to a monitoring, diagnostic, orstimulating device. The signal transmission pathway is adapted fortransmitting signals between the biomedical electrode and themonitoring, diagnostic or stimulating device.

Developments in electrically conductive fibers and textiles have made itpossible to incorporate a variety of electronics including, as will bediscussed herein, signal transmission pathways directly into wearableclothing. Metallic fibers with a very low resistance to electricalcurrent may be woven into otherwise non-conductive fabrics allowing thefibers to be individually addressed like the wires in a cable. Theseconductive fibers may carry data signals or power and allow for theconnection of traditional electrical components by conventional means.Furthermore, traditional stitching techniques such as embroidery may beused with electrically conductive threads to create electrical traces.Some of these devices may even be designed to withstand the stress oflaundering.

The present disclosure describes a garment providing a means for thesimple connection to externally placed physiological sensors on thehuman body that can transmit electronic signals to and from the body.The garment is also equipped with an EMI shield which protects thesignal transmission pathways from the interference associated withelectromagnetic fields. The garment is either disposable or washable.

The garment includes a comfort layer which is described as the garmentmember herein. The garment member provides a substrate or a canvas towhich conductive thread, connectors, adapters, an EMI shield or othercomponents may be affixed. Connectors are provided at various locationson the garment member which provide a connection means to physiologicalsensors or other externally placed electrodes on the body. Theconnectors are electrically attached to signal transmission pathwaysformed from a conductive thread stitched into the garment member. Thesignal transmission pathways lead to an adapter or adapters whichprovide a connection means to external monitoring or stimulatingequipment. Finally, the signal transmission pathways are covered on theinterior and exterior surface of the garment member by an EMI shieldformed from a wearable fabric.

In one embodiment, the garment member takes the form of a vest or shirtwhich may be worn during ECG monitoring. Conductive thread is stitchedinto the garment member in a pattern that allows biopotential signalsfrom standard 3, 5, 7, or 12-lead configurations to be transmitted to anadapter at the waist of the subject. The signal transmission pathwaysare stitched in a pattern such that each pathway is isolated from theothers and each pathway is covered by a fabric based EMI shield. Thegarment member is made from a light weight material such as cotton orpolyester providing the subject with comfort and ease of movementwithout undue pulling on the sensor sites.

In another embodiment, the garment member takes the form of a fulllength sports bra. This embodiment naturally lifts the breasts andallows a clinician to correctly place electrode leads in the areaunderneath the breasts. Another embodiment is a bonnet worn over thehead to obtain electroencephalography (EEG) signals. Still anotherembodiment is a shirt with full length sleeves. This embodiment allowsfor sensors such as pulse oximetry probes, temperature probes andglucose monitors to be placed on the hands and wrists.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the presentdisclosure and, together with the detailed description of theembodiments given below, serve to explain the principles of thedisclosure.

FIG. 1A is a front view of an embodiment of the present disclosure as avest on a subject;

FIG. 1B is an enlarged view of a sensor site depicting a flap refinementof the vest depicted in FIG. 1;

FIG. 1C-FIG. 1F depict exemplary stitch patterns which may be suitableto create the signal transmission pathways of FIG. 1A.

FIG. 2A is a front view of an embodiment of the invention as a fulllength sports bra on a subject;

FIG. 2B is an enlarged view of the sports bra of FIG. 2A depicting arefinement;

FIG. 3A is a cross-sectional view of signal a transmission pathwayprotected with an EMI shield;

FIG. 3B is a view similar to view 1B depicting the EMI shield used inconjunction with the flap refinement;

FIG. 4A is a front view of another embodiment of the present disclosureas a washable or disposable garment;

FIG. 4B is a front view of an electrode array and a monitoring,diagnostic or stimulating device for use with the garment of FIG. 4A;and

FIG. 5A is a front view of a standard 12-lead configuration of atraditional prior art ECG monitoring system.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The attached figures illustrate exemplary embodiments of the presentdisclosure and are referenced to describe the embodiments depictedtherein. Hereinafter, the disclosure will be described in detail byexplaining the figures wherein like reference numerals represent likeparts throughout the several views.

The exemplary embodiments of the apparatus disclosed herein arediscussed in terms of performing a diagnostic or therapeutic procedureinvolving collecting or delivering electrical signals relative to asubject. Such procedures are inclusive of, but, not limited toelectrocardiograph procedures, maternal and/or fetal monitoring, and avariety of signal based rehabilitative procedures. However, it isenvisioned that the present disclosure may be employed with manyapplications including surgical, diagnostic, and related treatments ofdiseases and body ailments of a subject.

In the discussion that follows, the term “subject” refers to a humanpatient or other animal. The term “clinician” refers to a doctor, nurse,or other care provider and may include support personnel.

Referring initially to FIG. 1A, an embodiment of the present inventionis depicted as a vest 10 donned by a subject. Vest 10 has application inat least 3, 5, 7, or 12-lead ECG monitoring systems and is depicted herein a 12-lead system. The vest includes a garment member 100, an adapter110, several connectors 130, several signal transmission pathways 120connecting the adapter to the several connectors, and an EMI shield 140covering the signal transmission pathways. The garment member 100 may bemade from a non-conductive lightweight material such as cotton orpolyester. This layer provides the subject the comfort and ease ofmovement that is provided by typical clothing while providing asubstrate for the other components. Connectors 130 are positionedthroughout the vest 10 at sensor sites where an external electrode maybe placed on the body of the subject. The sensor sites are selectedappropriately for the particular type of signal to be monitored ortransmitted through the electrode, and each electrode may be selectedindividually to transmit a different type of signal. The connectors 130are adapted to make physical contact with the leads of the electrodesand ensure electrical continuity therewith. Connectors may be anyindustry standard devices such as snaps, pinch-clips and alligator clipsmay be appropriate selections for connectors 130. Each connector willlikely have leads (or another interface) opposite the functional endwhich will be attached to the signal transmission pathways 120.

The leads 131 of the connectors 130 may be attached to the first ends ofsignal transmission pathways 120 by stitching the leads onto the garmentmember 100 using a conductive thread. As used herein, the term“stitching” includes any type of sewing or needlework in which aflexible fiber or bundle of fibers is passed through a substrateconnecting the fiber or bundle of fibers to the substrate. This includesembroidery, needle-punching and the like. Here, the leads are stitchedto the garment member 100 with a conductive thread to ensure electricalcontinuity with the conductive thread. This may be the only means bywhich the connector is affixed to the garment member. Alternatively,additional non-conductive stitching or other conventional means may beused in combination. The conductive stitching is continued in adirection toward the adapter 110 to form the signal transmission pathway120. The stitching for the signal transmission pathway 120 may take theform of a zig-zag stitch where the conductive thread is shiftedlaterally with respect to the general direction of the pathway as shownin FIG. 1C. This type of stitching may allow the garment member 100 tomaintain much of its inherent flexibility. Other types of stitches whichcan accomplish this include, but are not limited to, an elastic blindhem stitch (FIG. 1D), a platform stitch (FIG. 1E), and stem stitch (FIG.1F). Regardless of the type of stitching selected, each signaltransmission pathway 120 should be isolated spatially and electricallyfrom the other pathways. The conductive stitching may again be used atthe second ends of signal transmission pathways 120 to affix the leadsor interface of the adapter to the garment member. Alternatively theadapter 110 may be a clam-shell design that clamps over the conductivethreads. In this way, the electrical continuity may be establishedbetween the electrodes on the body of the subject and the adapter 110.The adapter 110 may then be connected to external monitoring orstimulating equipment establishing electrical continuity between thesubject and the external equipment.

The conductive thread used can be any number of materials commonly usedin the garment industry for decorative purposes containing conductivemedia such as silver, copper, nickel, and carbon. Commercially availableproducts include a variety of threads with the flexibility, durabilityand low electrical resistance which are suitable for creating a signaltransmission pathway 120.

Finally FIG. 1A depicts an EMI shield 140 covering the connectors 130and signal transmission pathways 120. As shown a single piece of EMIshielding cloth is affixed to the garment member 100 covering each ofthe connectors 130 and signal transmission pathways 120, but it is to beunderstood that each component may have its own shield. An appropriateEMI shield will be selected primarily to prevent interference fromelectromagnetic fields in the signal transmission pathway 120. A textilebased EMI shield might consist of a weave of cotton and metallic fiberswherein the metallic fibers constitute an appropriate proportion of theweight of the fabric. The fabric should be capable of redirecting amagnetic flux away from the signal transmission pathways 120, have thenormal qualities of clothing and be suitable for the fabrication ofgarments normally worn in contact with the skin. With reference to FIG.1B, connector 130 is positioned in a flap 150 near the sensor site. Flap150 at least partially covers an aperture 160 in the garment memberwhich surrounds the sensor site. Because of the inherent flexibility inmaterial composing the garment member, flap 150 is movable between aposition wherein the flap substantially covers the aperture 160, and aposition where the aperture is left substantially uncovered. This flapand aperture arrangement allows a clinician to view the electrodeplacement on the skin, or attach or remove an electrode without removingthe garment. Additionally this provides strain relief to the electrodeby reducing the multi-directional pull exerted by the garment.

Referring now to FIG. 2A, an embodiment of the present invention isdepicted as a full length sports bra 20 donned by a subject. The sportsbra includes a garment member 200, an adapter 210, several connectors230, several signal transmission pathways 220 connecting the adapter tothe several connectors, and an EMI shield 240 covering the signaltransmission pathways.

As indicated in FIG. 2B, the bra portion of the garment naturally liftsthe breasts with a support means 270. Support means 270 may be anunderwire or elastic member which provides access to an aperture 260under the left breast. The garment then frees the clinician from havingto lift the breast, which clinicians often feel uncomfortable doing, andenables clinician to properly place electrodes in the area. Also evidentfrom FIG. 2B is that aperture 260 may encompass several sensor sites andaccommodate multiple flaps 250 and connectors 230.

Referring now to FIG. 3A, a cross section of transmission pathway 320 isdepicted. Conductive stitching forms the transmission pathway 320 whichprotrudes on each side of garment member 310. A fabric EMI shield 340 isplaced on both sides of the signal transmission pathway 320 so that oneshield is located on the interior of the garment and another on theexterior. For this reason, it is desirable that the shield on theinterior feel comfortable against the skin of the subject. Finally, FIG.3B depicts an aperture 360 which extends through garment member 310 andboth layers of EMI shield 340. The signal transmission pathway 320extends from the aperture in the normal manner.

Other embodiments of the present invention include a bonnet worn overthe head to obtain EEG signals, a shirt with full length sleevesallowing for sensors such as pulse oximetry probes, temperature probesand glucose monitors to be placed on the hands and wrists, or even asimple substantially flat patch which may be affixed anywhere on thebody with an appropriate strap or adhesive. Any of these embodiments mayinclude a fabric tab disposed within the adapter which is long enoughwhen extended to allow the garment to be plugged into externalequipment. Alternatively, an OEM equipment cable may be disposed withinthe adapter.

Referring now to FIG. 4A, an embodiment of a disposable or washablegarment 400 is depicted, which may be used to reduce the risk ofcross-infection from subject to subject. Near a lower end of the garment400 is adapter 410, which is in electrical communication with each often signal transmission pathways 420. As discussed above with referenceto preceding embodiments, each signal transmission pathway 420 is formedfrom a conductive thread 422 stitched into the garment 400. Conductivethread 422 is passed through garment 400 at appropriate intervals toaffix the conductive thread 422 to the garment 400. Consequently,regular segments of the conductive thread 422 appear on the exteriorside of the garment 400, while intermediate segments are concealed bythe non conductive substrate of the garment 410. For this reason, signaltransmission pathways 420 appear as dashed curved lines in FIG. 4A.Although a straight stitch is depicted in FIG. 4A, any stitching patternmay be selected.

Each signal transmission pathway 420 terminates at a connector 430, 433on the interior of the garment 400. Each shoulder of garment 400 isshown broken to reveal the interior space containing the connector 430,433. Connector 430 is simply formed as a minor lead segment bycontinuing conductive thread 422 a relatively short distance on theinterior of garment 400. A connector 430 in this form facilitateslaundering of the garment 400 and may be reinforced to withstandrepeated laundering. Alternatively, connector 433 may be provided in theform of an alligator clip as shown. The alligator clip has a leadstitched onto garment 400 with the end of the conductive tread 422forming the signal transmission pathway. A snap connector or any otherconvenient type of connector may be used for facilitating electricalcoupling with a biomedical electrode such as the ECG electrodes depictedin FIG. 4B.

FIG. 4B depicts a biomedical electrode array 490 formed from ten ECGelectrodes 492 arranged on a subject 494 according to a standard 12-leadconfiguration. A lead of each electrode 492 is equipped with analligator clip 496 and is in electrical communication therewith. Eachalligator clip 496 is provided to facilitate electrical connection ofelectrode array 490 with a garment 400 having connectors 490 in the formof a minor lead segments. Alligator clips 496 may not be required ifsimilar connectors 433 are provided on garment 400.

Also depicted in FIG. 4B is a monitoring, diagnostic or stimulatingdevice 497 for monitoring the electrical signals received fromelectrodes 492. Monitoring, diagnostic or stimulating device 497 isequipped with cable 499 adapted to mechanically and electricallyinterface with adapter 410. When all necessary electrical connectionsare made, electrical continuity may be established from monitoring,diagnostic or stimulating device 497 to the subject 494 through cable499, adapter 410, signal transmission pathways 420, connectors 430,alligator clips 496 and electrodes 492.

A traditional prior art electrode array 590, as depicted in FIG. 5, isequipped with ten ECG electrode leadwires 599, commonly reusable frompatient to patient Leadwires 599 may not be adequately cleaned betweenuses, increasing the risk of cross-infection. In this embodiment, thesignal transmission pathways 420 may serve as ECG electrode lead wires.In contrast, in the embodiment shown in FIGS. 4A and 4B, garment 400 maybe cleanable or disposable to reduce the risk of cross-infection fromsubject to subject. Additionally, stitching the conductive thread intogarment 400 to form signal transmission pathways 420 replaces thecumbersome electrode leads 599 of traditional systems.

Although the foregoing disclosure has been described in some detail byway of illustration and example, for purposes of clarity orunderstanding, it will be obvious that certain changes and modificationsmay be practiced within the scope of the appended claims.

1. An apparatus for facilitating connection of a biomedical electrodearray having one or more electrodes to a monitoring, diagnostic, orstimulating device, which comprises: a garment member for positioningrelative to a body portion of a subject; at least one signaltransmission pathway including a conductive thread stitched into thegarment member such that the conductive thread is passed through thegarment member to connect the signal transmission pathway to the garmentmember, the at least one signal transmission pathway having a first endconnectable to an electrode and a second end connectable to themonitoring, diagnostic, or stimulating device, the at least one signaltransmission pathway adapted for transmitting signals between theelectrode and the monitoring, diagnostic, or stimulating device.
 2. Theapparatus according to claim 1 wherein the electrode is an ECGelectrode.
 3. The apparatus according to claim 1 including a pluralityof signal transmission pathways stitched into the garment member fortransmitting signals between respective electrodes and the monitoring,diagnostic or stimulating device.
 4. The apparatus according to claim 3including a connector associated with the first end of each of thesignal transmission pathways for connection to a respective electrode.5. The apparatus according to claim 4 wherein at least one connector isin the form of a minor lead segment.
 6. The apparatus according to claim4 wherein at least one connector is in the form of an alligator clip. 7.The apparatus according to claim 1 including an adapter associated withthe second ends of the signal transmission pathways, the adapter forelectrical connection to the monitoring, diagnostic or stimulatingdevice.
 8. The apparatus according to claim 7 including a tab connectedto the second ends of the signal transmission pathways, the tab adaptedfor electrical connection to the adapter.
 9. The apparatus according toclaim 1 including an EMI shield layer mounted adjacent the garmentmember and at least partially enclosing the signal transmissionpathways.
 10. The apparatus according to claim 9 wherein the EMI shieldlayer is affixed to the garment member.
 11. The apparatus according toclaim 1 wherein the garment member includes at least one flap, the flapmovable to permit access to an electrode positioned adjacent thereto.12. The apparatus according to claim 11 including a connector mounted tothe flap and in electrical connection with the first end of one of theplurality of signal transmission pathways, the connector for connectionto the electrode.
 13. The apparatus according to claim 1 wherein thegarment member is a shirt or vest adapted for placement about thesubject's torso.
 14. An apparatus for connection to a biomedicalelectrode array having a plurality of biomedical electrodes, whichcomprises; a garment member for positioning relative to a body portionof a subject; a plurality of signal transmission pathways, each pathwayincluding a conductive thread stitched into the garment member such thatthe conductive thread is passed through the garment member to connectthe signal transmission pathway to the garment member, and each pathwayadapted to transmit an electrical signal; a plurality of electrodeconnectors mounted relative to the garment member and electricallycoupled with respective signal transmission pathways, the electrodeconnectors adapted for connection to respective biomedical electrodespositionable on the subject; and an adapter for electrically couplingthe signal transmission pathways to an external monitoring orstimulating device.